strings.zfill(a, width)
Return the numeric string left-filled with zeros. A leading sign prefix (+/-) is handled by inserting the padding after the sign character rather than before.
Parameters:aarray-like, with StringDType, bytes_, or str_ dtypewidtharray_like, with any integer dtypeWidth of string to left-fill elements in a.
Returns:outndarrayOutput array of StringDType, bytes_ or str_ dtype, depending on input type
Examples
>>> importnumpyasnp>>> np.strings.zfill(['1','-1','+1'],3)array(['001', '-01', '+01'], dtype='<U3')